A concern in the design of tiled LED display systems having LED modules, sometimes termed LED module boards, is the appearance of “dark line” defects in the seam between adjacent LED modules, especially between LED modules across adjacent LED tiles. Dark line defects refer to the visible dark lines that are sometimes visible to a viewer where the spacing between adjacent LED modules is too great for the adjacent LED modules to create the impression of a continuous image from one LED module to the next. The maximum module spacing error beyond which such dark line defects are perceived is typically approximately of 5% of the nominal pixel pitch of the LED modules. For example, a 1.2 mm nominal pixel pitch gives rise to a spacing error of 1.2×0.05=0.06 mm (60 um) such that a pixel pitch of 1.26 mm or less across module boundaries is required to avoid the perception of dark line defects by a viewer.
LED modules arranged in a tiled LED display system are therefore often spaced closely together, with minimal allowable spacing error, to avoid the appearance of dark line defects. This requirement to tightly space LED modules together results in challenging design, manufacturing, and installation requirements. Even where such requirements are followed, the occurrence of dark line defects can persist.